Maximal treadmill exercise with measurement of expired gases has been performed in, more than 600 clinically normal BLSA volunteers over the past 5 years. Although a formal data analysis is currently in progress, it appears that the strong age-related decline in both maximal heart rate and maximal aerobic capacity (VO2max) noted in small BLSA samples will be confirmed. However, age-related changes in V02max are attenuated markedly when V02max is normalized for muscle mass. To determine the role of catecholamines in the well known age- related decline in exercise capacity, we measured plasma norepinephrine (NE) and epinephrine (E) at rest and during maximal treadmill exercise in 24 healthy men. Resting NE was not age-related but resting E was higher in men 68-77 years old than in those 22-37 or 44-55 years of age. At maximal effort both NE and E were higher in the elderly men. Furthermore, at submaximal workloads NE and E increased with age, both before and after normalization for relative effort as a percent of peak V02. In another study, the metabolic effect of relatively prolonged aerobic exercise, is being assessed in healthy men. The relationship of VO2max to blood lipid levels and blood pressure is being determined in the entire active BLSA population via a multivariate analysis done in collaboration with the Metabolism Section, LCP.